A Modified Blood Pressure to Height Ratio Improves Accuracy for Hypertension in Childhood

BACKGROUND: The blood pressure to height ratio (BP:HT) has been proposed as a simple method for identifying children with elevated BP. This procedure shows good accuracy for the screening of hypertension in adolescents but less so in younger children. Our aim in this study was to modify the BP:HT ratio and determine if this change would increase accuracy when measuring hypertension during childhood. METHODS: BP levels of 4,327 children (aged 5-12 years) were retrospectively obtained from medical charts. The modified ratio (BT:eHT13) was calculated as: BP/(HT + 7 × (13 - age in years)). Receiver operating characteristic curves were used to estimate cutoff points and the accuracy of the conventional and modified ratio to detect prehypertension and hypertension. RESULTS: The prevalences of prehypertension and hypertension were 3.91% and 5.44%, respectively. In general, BP:eHT13 showed higher sensitivity (ranging from 0.95 to 1.00) and specificity (ranging from 0.80 to 0.98) in detecting prehypertension, level I hypertension, and level II hypertension than BP:HT (sensitivity ranging from 0.91 to 1.00; specificity ranging from 0.59 to 0.89). CONCLUSIONS: The modified BP:eHT13 ratio showed better sensitivity and specificity for the screening of BP abnormalities in children aged 5-12 years.